China has shifted into a stage of high-quality development, and there is a long way to achieve sustainable development. This article uses a coupling coordination degree model to quantitatively analyze green finance and high-quality development, two subsystems in Yangtze River Economic Belt in China, and measure the level of coordinated development between the two subsystems from 2012 to 2019. The following results were obtained: (1) green finance in the Yangtze River Economic Belt has promoted industrial green development, and high-quality economic development has significantly fed back green finance, achieving a Good Coordination Coupling between the two; (2) green finance plays an oriented role in green industrial layout and regional green technology innovation and entrepreneurship, and high-quality development helps financial institutions innovate green financial products; (3) green finance has a significant effect on high-quality economy of upstream regions to form a regional cooperation mechanism, and green industries develop rapidly, as their coupling coordination has increased the most dramatically since 2012. This article can provide policy recommendations for provincial governments in various regions, help identify favorable factors for coordinated development, and improve the role of some influencing factors in a targeted manner, thereby strengthening the role of green finance in regional green technology innovation and entrepreneurship, and ultimately achieving sustainable development.